A gutta is a small water-repelling, cone-shaped projection used near the top of the architrave of the Doric order in classical architecture. At the top of the architrave blocks, a row of six guttae below the narrow projection of the taenia (fillet) formed an element called a regula. A regula was aligned under each triglyph of the Doric frieze. In addition, the underside of the projecting geison above the frieze had rectangular protrusions termed mutules that each had three rows of six guttae. These mutules were aligned above each triglyph and each metope.